Vertical and Horizontal Jump Tests Are Strongly Associated With Competitive Performance in 100-m Dash Events

Abstract

Loturco, I, Pereira, LA, Cal Abad, CC, D'Angelo, RA, Fernandes, V, Kitamura, K, Kobal, R, and Nakamura, FY. Vertical and horizontal jump tests are strongly associated with competitive performance in 100-m dash events. J Strength Cond Res 29(7): 1966–1971, 2015—Fourteen male elite sprinters performed short-distance sprints and jump tests until 18 days before 100-m dash competitions in track and field to determine if these tests are associated with 100-m sprint times. Testing comprised of squat jumps (SJ), countermovement jumps (CMJ), horizontal jumps (HJ), maximum mean propulsive power relative to body mass in loaded jump squats, and a flying start 50-m sprint. Moderate associations were found between speed tests and competitive 100-m times (r = 0.54, r = 0.61, and r = 0.66 for 10-, 30-, and 50-m, respectively, p ≤ 0.05). In addition, the maximum mean propulsive power relative to body mass was very largely correlated with 100-m sprinting performance (r = 0.75, p < 0.01). The correlations of SJ, CMJ, and HJ with actual 100-m sprinting times amounted to −0.82, −0.85, and −0.81, respectively. Because of their practicality, safeness, and relationship with the actual times obtained by top-level athletes in 100-m dash events, it is highly recommended that SJ, CMJ, and HJ be regularly incorporated into elite sprint-testing routines.

Introduction

Performance variance in endurance running competitions is largely explained by the triad maximal oxygen consumption, lactate threshold, and running economy (¹⁹). For this reason, training intervention studies have aimed at improving these variables in isolation or in combination to enhance the athletes' performance (^31,35). Surprisingly, to our knowledge, there are no studies investigating the associations between physical or physiological traits and competitive performance in sprinters, especially at the top level. Therefore, finding competitive performance correlates in a relatively homogeneous group of sprinters is still a challenge. This is especially important at a time when upper human performance in the 100-m sprint is being discussed because of the astonishing times obtained by both male and female athletes (¹⁶).

The sprint exercise is predominantly supplied by the anaerobic turnover of adenosine triphosphate, with a significant drop in muscle pH and elevation in oxygen consumption (^2,5). Anaerobic capacity, as measured by maximal oxygen deficit, partly determines success in sprinting (²⁹). However, this capacity has to be coupled with the ability to increase the rate of anaerobic energy release (³⁶) (i.e., anaerobic power). Additionally, from a mechanical point of view, forces applied during the foot-ground contact are related to the ability to reach top speeds (³⁷). The combined metabolic and mechanical factors related to sprinting cannot be fully manifested without the large prevalence of fast twitch fibers in the lower limb muscles (²²) and training-related neural adaptations inherent to fast muscle activation (³²). Similar characteristics seem to determine performance in other explosive tasks such as vertical jumps (VJ) (^14,24). Therefore, positive associations are expected between jumping and sprinting abilities.

The scarce literature using less qualified sprinters evidenced that VJ and drop-jump outcomes combined with the reactive strength index explained 89.6% of mean velocities in several sprinting distances (³⁴). In top-level sprinters, loaded and unloaded jumping performances were highly correlated with the speed reached by elite sprinters in the tests of up to 50 m (^13,23). From these results, it was suggested that strength-power development is important for athletes to achieve higher velocities over short distances (²³). It remains to be established whether actual performance in 100-m and personal bests are related to jumping ability. A recent editorial published in a sports science journal (¹¹) claimed that regarding monitoring tools, cost-effective and time-effective systems resulting in simple practices should be sought rather than unnecessary complex systems. This is even more important in developing countries with low resources to assess athletes in sports disciplines like track and field sprinting.

Therefore, the purpose of this study was to ascertain whether, for top-level sprinters, the actual performance in 100-m dash competitions is associated with neuromechanical capacities measured by specific short-distance speed assessments and jump tests (in loaded and unloaded conditions). Based on extensive published data confirming the strong correlations between various neuromuscular measures and sprinting ability (^{12,18,20,23,26}), we hypothesized that jump performance-related metrics would be significantly correlated with 100-m sprint times.

Methods

Experimental Approach to the Problem

This study used a cross-sectional correlational design to describe and explore the relationships between speed and VJ test results (in loaded and unloaded conditions), and actual 100-m dash performance in top-level sprinters. All sprinters were familiar with the testing procedures, which were carried out during the competitive training period, from 14 to 18 days before competitions where actual performance was measured. Before the tests—executed on the same day—the athletes performed 20 minutes of general and specific warm-up, including moderate running (10 minutes), active stretching (5 minutes), and specific sprint drills (5 minutes). The order of the evaluations was as follows: test 1, squat jumps (SJ) and countermovement jumps (CMJ); test 2, horizontal jumps (HJ); test 3, sprinting speed; and (90 minutes afterward) test 4, mean propulsive power (MPP) in jump squats. The athletes received standard instructions on required pretest behavior, including a minimum of 8-hour sleep, balanced nutrition, and avoidance of beverages or food containing alcohol and caffeine.

Subjects

Fourteen male elite sprinters (age range: 24.9 ± 3.8 years, height: 178.7 ± 6.4 cm, and body mass [BM]: 77.8 ± 8.5 kg) volunteered to participate in the study. The sample comprised of elite athletes who participated in Olympic, Pan-American, and South American Games, with personal records, on average, 7% longer than the men's 100-m world record (i.e., ≈10.28 ± 0.10 seconds), thus attesting their high level of competitiveness. Athletes were briefed on the experimental risks and benefits of the study and signed a written informed consent agreeing to take part. The study was approved by the local ethics committee.

Vertical Jumps

Vertical jumps were assessed with the hands on the hips, using SJ and CMJ. For SJ, a static position with a 90° knee flexion angle was maintained for 2 seconds before each attempt without any preparatory movement. For CMJ, the sprinters performed a downward movement followed by a complete extension of the lower limbs, freely determining the amplitude of the countermovement. Five attempts at each jump were performed on a contact platform (Smart-Jump; Fusion Sport, Brisbane, Australia), interspersed by 15-second intervals. The obtained flight time (t) was used to estimate the VJ height (h) (i.e., h = gt²/8). The best attempt was retained for further analysis.

Horizontal Jumps

Sprinters performed the HJ starting from a standing position. They commenced the jump by swinging their arms and bending their knees to provide maximal forward drive. A take-off line was drawn on the ground, positioned immediately adjacent to a jump sandbox. The jump-length measurement was determined using a metric tape measure (Lufkin, L716MAGCME; Apex Group, Sparks, Maryland), from the take-off line to the nearest point of landing contact (i.e., back of the heels). Each athlete executed 3 attempts, and the longest distance was considered.

Jump Squats

Mean propulsive power was assessed in the jump squat exercise executed on a Smith-machine (Technogym Equipment, Cesena, Italy). Athletes performed 3 repetitions at maximal velocity for each load, starting at 40% BM; with loads of 10% BM progressively added in each set until a decrease in MPP was observed. Subjects executed a knee flexion until the thigh was parallel to the ground, then, after a command, jumped as quickly as possible without their shoulder losing contact with the bar. A 5-minute interval was provided between sets. A linear transducer (T-Force; Ergotech, Murcia, Spain) attached to the Smith-machine bar was used to obtain the MPP. The bar-position data were sampled at 1,000 Hz using a PC (Toshiba, Tokyo, Japan). Mean propulsive power rather than peak power was used because Sanchez-Medina et al. (³³) observed that these mechanical values during the propulsive phase better reflect the differences in neuromuscular potential between individuals. This method avoids underestimation of the true strength potential as the higher the mean velocity (and lower the relative load), the greater the relative contribution of the braking phase to the entire concentric time. The relative values of MPP (MPPR) were obtained by dividing the higher values of MPP by the athletes' BM (W·kg⁻¹).

Speed Testing

Sprinters performed 2 attempts at a flying start 50-m test to assess maximum speed, with a 5-minute interval between attempts. Four pairs of photocells (SmartSpeed; Fusion Equipment, Brisbane, Australia) were positioned at distances of 0-, 10-, 30-, and 50-m. Athletes started each attempt 5 m behind the first photocell timing-gate, accelerating as much as possible before crossing the starting line. The best 50-m performance was retained.

Statistical Analyses

Data are presented as mean ± SD. A Pearson's product moment correlation coefficient was used to analyze the relationships between jump and speed test results and actual sprinters' performances during competition. The threshold used to qualitatively assess the correlations was based on Hopkins (¹⁷), using the following criteria: <0.1, trivial; 0.1–0.3, small; 0.3–0.5, moderate; 0.5–0.7, large; 0.7–0.9, very large; and >0.9, nearly perfect. Data normality was checked by the Shapiro-Wilk test. The statistical significance level for all the analyses was set at p ≤ 0.05, using the 2-tailed test of significance. Intraclass correlations (ICCs) and coefficient of variation were used to indicate the reproducibility of SJ, CMJ, HJ, and jump squats for height, distance, and MPP.

Results

All data presented normal distribution (p > 0.05). The ICC for the jump squats, SJ, CMJ, HJ, and sprint times in 10-, 30-, and 50-m were all >0.90. The coefficient of variation for all variables analyzed was lower than 1%.

Table 1 presents the mean (SD) and the 95% confidence interval of the SJ, CMJ, HJ, MPPR, and the sprint times at 10-, 30-, and 50-m and competitive 100-m dash time. Table 2 shows the correlations between MPPR and short-distance sprint tests (10-, 30-, and 50-m) with actual 100-m performance. Large associations were found between speed tests and competitive 100-m times (r = 0.54, r = 0.61, and r = 0.66 for 10-, 30-, and 50-m, respectively, p ≤ 0.05). The MPPR was very largely correlated with 100-m sprinting performance (r = 0.75, p < 0.01). Figure 1 depicts the correlations between SJ, CMJ, and HJ and 100-m dash times. The jump tests were very largely associated with 100-m dash performance (r = −0.82, r = −0.85, and r = −0.81 for SJ, CMJ, and HJ, respectively, p < 0.01).

Table 1: Descriptive analysis (mean, SD, and 95% CI) of the jumps in loaded and unloaded conditions, and short-distance sprint tests.^*

Table 2: Correlations between short-distance sprints (at 10-, 30-, and 50-m), MPPR, and actual 100-m dash times.^*

Figure 1: Correlations between vertical (unloaded conditions) and horizontal jump tests with actual 100-m dash times (r = -0.82, -0.85, and -0.81 for SJ, CMJ, and HJ, respectively; p < 0.01).

Discussion

This study aimed to identify potential factors associated with sprinters' performance in official competitions. The main finding of this investigation was that, simple vertical and HJ test outcomes are very largely associated with actual 100-m dash performance in a sample composed of male top-level sprinters, provided they are executed few days (∼2 weeks) before the competition. Moreover, the relative outputs of MPP collected during jump squats demonstrated a correlation of −0.75 with actual speed achieved by these athletes. Importantly, despite their apparent specificity, the “partial-distance velocity tests” have only a moderate correlation with 100-m dash times.

The fact that practical jump tests are related to competitive sprinting performance is very remarkable. Sprint training methods are full of technology, and the possibility of monitoring sprinters' athleticism using nonexpensive tests especially favors the track and field programs developed across emergent countries. Similarly, even the leading sports nations may benefit from this method, because head coaches and strength and conditioning specialists avoid assessing athletes' speed close to competitions because of the high risk of injury involved in all-out tests.

Despite the simplicity of the assessments, unloaded jump tests (SJ, CMJ, and HJ) had stronger associations with sprinting performance than MPPR. It must be mentioned that the MPPR is measured “on the barbell,” and it does not reflect the actual power output of a given movement (^8,9,27). Conversely, jump heights are measures able to express values already corrected by the body weight. If during a VJ a subject jumps higher, he necessarily produces higher values of relative force and relative power (N·kg⁻¹ and W·kg⁻¹, respectively) than his weaker counterpart (^3,7). To achieve maximal height during a jump attempt, the athlete's center of mass needs to be as high as possible (in relation to the ground), attaining the highest vertical velocity at the takeoff (¹⁵). At this moment, the subject follows a sequential pattern of lower limb segmental rotation, resulting in a great amount of external forces, which are applied to overcome the inertia and accelerate the body vertically (⁶). As the ground reaction force increases, the jump height increases. Equally, the transition from lower to higher velocities (i.e., top-speed sprinting) results in shorter support phase duration with a concomitant increase in vertical peak force (²⁸). In addition, the distances achieved during HJ are dependent on the athletes' ability to transfer the linear momentum of force directly from the ground to the peak horizontal acceleration of the body's center of mass, which is also critical to break the inertia and attain high velocities over short distances (^4,18,23). It is reasonable to assume that these mechanical relative values tend to be more associated with the sprinters' actual performance, because they have to push their bodies forward as rapidly as possible during the competitions, applying great amounts of force against the ground.

The strong relationship between MPPR and 100-m sprint times (r = −0.75) cannot be overlooked. However, loaded jump testing may be potentially dangerous for athletes when performed for a short time before competitions (³⁰). Differently from unloaded conditions (SJ and CMJ), jump squats using loads close to or higher than BM may represent risks to joints and spine, by substantially increasing the ground reaction forces at the landing moment (³⁸). To some extent, the stronger values of correlation coefficients (with 100-m times) presented by CMJ and SJ (r ≈ −0.84) when compared with loaded conditions (r = −0.75, for MPPR) may be explained by the mechanical principles involved in these assessments. The jump height is entirely related to the body's vertical acceleration, and the acceleration is equal to force divided by mass (i.e., sprinter's weight) (²¹). As a result, for unloaded circumstances, higher jumping heights not only indicate higher values of relative force, but also indicate superior capacities to accelerate one's own body weight (¹). Conversely, during jump squats, the power outputs (MPPR) are directly collected from the barbell, which do not reflect the actual mechanical values (i.e., acceleration and velocity) of the athletes' body center of mass during a given movement (¹⁰). It is conceivable that these mechanical differences may influence our findings, resulting in stronger associations between sprinting times and unloaded VJs. Finally, the “loaded jump squat” evaluations are long-lasting and involve expensive equipment (i.e., linear position transducers), limiting their usefulness in the field, whereas unloaded jump heights can be measured by simple “vertical jump-and-reach tests” (⁸). Nevertheless, both unloaded and loaded jump squats are fed by the immediate energy supply from the intramuscular phosphagens and require the neural control inherent to ballistic movements that are also important in sprinting (^32,36).

In addition to the aforementioned weaker correlations with actual sprint times, all-out speed assessments also involve inherent risks (e.g., muscle and tendon injuries). It is likely that closer proximity to competitions contributes to raising the fear presented by coaches and athletes when executing speed tests, thus compromising their outcomes and reducing the correlations between “sprint-test times” and “sprint-competition times.” This is because of the fact that top running speeds are related to high ground reaction forces rather than more rapid repositioning of limbs in the air, meaning that the will to maximally engage neuromuscular abilities is a prerequisite for achieving best performances in all-out speed tests (³⁷). Increases in the magnitude of the eccentric forces—and consequently, in the ground reaction forces—at the landing moment during the “loading stance phase” may result in undesirable injury risks (²⁵).

This study is limited by the relatively small sample size. However, to our knowledge, this is the first study testing the relationship between unloaded and loaded jump test performances and actual competitive performance in high-caliber athletes. Hence, interpretation of the results should take this important aspect into account.

To conclude, as long as they are executed few weeks before the competitions, vertical and HJ tests are directly related with 100-m dash times. The results presented herein confirm that coaches are able to determine the readiness of their athletes for 100-m performance by using simple SJ, CMJ, and HJ. Short-distance speed test results and jump squat power outputs (MPPR) have weaker correlations than unloaded jump heights and distance (SJ, CMJ, and HJ) with actual sprinting performance. Additionally, these measurements involve a number of intrinsic problems, such as injury risks, assessment time required, and expensive equipment costs. Finally, with the stronger correlations presented by practical unloaded jumps, these assessments should be considered reliable enough to be related to actual sprinting times in highly competitive sprinters.

Practical Applications

From a practical perspective, simple jump tests can be used to assess the readiness of the sprinters' neuromuscular system to perform better during official competitions. Anecdotally, assessing performance using these tests is a common practice in track and field; however, it is possible that coaches are not aware of the strong and real potential of the outcomes to forecast forthcoming competitive sprinting results. Therefore, we suggest that measuring lower limb explosiveness by means of unloaded VJs (SJ and CMJ) and HJ may be useful in training and testing routines, because of their safeness and ability to strongly explain 100-m dash performance in top-level athletes. Further longitudinal studies are needed to fully elucidate the validity of jump tests in predicting changes in sprinters' performance (i.e., longitudinal validity) because of training and the potential effects of tapering and detraining periods on this relationship.